1. Field of the Invention
This invention relates to soluble oil concentrates for forming stable emulsions with water, and more particularly to soluble oil concentrates which are capable of forming stable emulsions of a minor part of concentrate and a major part of water, such as are used in roof support jacks in mines. Because of the use to which these emulsions are subjected, which in many cases involves standing static for thirty days or more in a mine roof support jack, the emulsions must have extremely good stability. Emulsions formulated according to this invention also have utility as cutting oils for machining operations.
2. Description of the Prior Art
There are numerous references in the literature describing soluble oil formulations for forming stable emulsions with water, U.S. Pat. Nos. 2,307,744; 2,470,913; 2,670,310; 2,695,272; 2,846,393; and 2,913,410 are representative of references describing emulsifiable oil compositions of the type to which this invention is directed. The compositions described in these prior art patents generally include mineral oil and an emulsifier package comprising an emulsifier, a coupling agent, and various additives. The composition described in U.S. Pat. No. 2,846,393 includes an emulsifier, mineral oil, alkali metal hydroxide, hexylene glycol, alkali metal resinate, and a sulfurized addend. This composition is stated to be compatible with both hard and soft waters and includes sodium mahogany sulfonate as the preferred emulsifier. The composition is primarily designed as a cutting oil, and the sulfurized addend is apparently included in order to provide proper lubrication for this purpose. While these prior art compositions have been quite satisfactory in many instances, there has nevertheless been a continuing need for an oil soluble concentrate capable of forming a stable emulsion, particularly for use in roof support jacks. Such a composition is provided by this invention.